A major revolution in video display technology includes flat screens based on either liquid crystal display (LCD) or plasma display panel (PDP) technology that are rapidly replacing the cathode ray tube (CRT) technology that served as the primary display device for more than a half a century. A significant consequence of the new video display technologies is that pictures may now be displayed at higher picture-rates with progressive scanning on a flat screen. The new video display technologies may also facilitate a faster transition from standard definition television (SDTV) to high-definition television (HDTV). However, legacy video compression systems still use formats with lower picture-rates and may be unable to optimally display legacy video on modern display screens.
An artifact known as “motion judder” may occur when the picture rate of a video sequence is excessively low. Motion judder may occur when the temporal sampling rate is too low to describe motion in a scene. The objects in input pictures may be shifted on either side of a required output picture. A temporal digital filter interpolation method may be used to determine pixel intensity values. The signals describing motion of each of the objects within a scene may be referred to as motion vectors. Each pixel or region with the same movement may be allocated a motion vector. The motion estimation system may determine these motion vectors and failing to find a correct motion vector and/or misusing the motion vector in a picture rate converter may lead to noticeable artifacts. When large camera movements occur, regions of a picture close to the borders may have significantly less reliable motion vectors than those closer to the middle and special processing may be required at the picture boundaries.
Telecine is a process that may be used to transfer film sequences to television. Telecine may involve a vertical low-pass Kell-factor filtering of a source image followed by a frame-rate conversion through field repetition. For NTSC, the first 3 fields may be received from the first film frame, followed by 2 fields from the second film frame, followed by 3 fields from the third film frame and so on. The non-uniformity of frames may cause motion judder. In cases where the telecine transfer maps the same number of fields to a single frame, a blurring or stuttering phenomenon may be present because of low temporal resolution of the source images and the near-simultaneous display of two temporally-disparate images.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.